IE2321 by Beckhoff

The IE2321 is a compact input/output extension box produced by Beckhoff within the IE Extension Box Units series. Designed for decentralized installation on machines, the module supplies sensor and actuator channels, forwarding field signals to the controller while isolating them from the bus system. By integrating power distribution and signal conditioning in a single enclosure, it reduces cabinet wiring and simplifies the expansion of digital I/O in industrial automation applications.

Each input line draws only 6 mA, so proximity switches and photoelectric sensors can be powered without exceeding standard sourcing limits. A built-in filter of 3.0 ms suppresses contact bounce and brief disturbances, presenting stable logic levels to the control task. The module offers 4 digital inputs that are galvanically separated from the fieldbus, providing isolation between the control and fieldbus circuits. Each inactive output stage absorbs a load current of 30 mA per channel, allowing the downstream driver to remain biased and ready. All channels share the module's rated load voltage of 24 VDC, so wiring can be connected in parallel with other 24-volt sensors and valve coils already present in the installation.

The transistor outputs deliver up to 2.0 A per channel, allowing them to actuate small motors, clutches, or high-current solenoids directly. A sensor auxiliary rail supplies 0.5 A per channel, eliminating the need for external power taps when feeding encoders or proximity devices in the same segment. For fault tolerance, each output can withstand a short-circuit current of 4.0 A, while the total current draw is limited to 4 A across the device. Process data are exchanged through a compact image containing 4 bits of input data and 4 bits of output data. M8 screw-in connectors provide vibration-resistant signal terminations and make the module easier to service while it is installed on a machine.